Security substrate incorporating elongate security elements

Abstract

The present invention is concerned with providing security substrates, and documents made therefrom, such as banknotes, with features for visual inspection by members of the public. More specifically the invention relates to a novel security substrate containing at least two elongate security elements for the purposes of public and non-public verification. The security substrate comprises a substrate and at least two elongate security elements each having a width of less than or equal to 6 mm. The security elements are at least partially embedded within the substrate and running substantially parallel to each other with a gap therebetween of no greater than 10 mm. The total cross-directional width of a zone occupied by the two security elements and the gap is less than or equal to 18 mm.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application is a U.S. national stage entry under 35 U.S.C. 371, of International Application No. PCT / GB2005 / 000173, filed Jan. 17, 2005. Priority in the International Application is claimed from UK Patent Application No. 0400984.1, filed Jan. 16, 2004. The content of both references is herein incorporated by reference.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention is concerned with providing security substrates, and documents made therefrom, such as banknotes, with features for visual inspection by members of the public. More specifically the invention relates to a novel security substrate containing at least two elongate security elements for the purposes of public and non-public verification.[0004]2. Description of the Related Art[0005]The inclusion of elongate elements, or security threads, into security paper is well known and has been widely described in the prior art. Such threads m...

AI Technical Summary

Benefits of technology

[0018]The ability to see a security feature is in part dependant on the area it covers. When two or more security elements are situated in close proximity such that they both appear near the centre of the field of vision, the viewer perceives the feature as covering an area bounded by the two outermost security elements. This area is greater than the area of the individual security element and is thus more likely to be noticed.

[0019]Where two or more security elements in close proximity lead to a more complex visual effect than the separate viewing of the individual security elements, the viewer is drawn to “investigate” the feature. This is because it represents an unexpected visual experience. The “chequer board”example demonstrates this effect (see FIG. 6 and the corresponding description below).

[0020]When the security feature comprises two or more security elements in close proximity at least one of which is more visible that the other(s), the viewer is first drawn to the more visible feature and, as a consequence, then sees the less visible security element(s). An example of this is two security elements running in close proximity one of which is embedded (less visible) and the other is windowed (more visible).

[0021]This effect is based on the observation that when two security elements in close proximity comprise a windowed security element and an embedded security element, the viewer is surprised when the

Problems solved by technology

One problem which can arise in the production of windowed paper is where the threads are embedded in exactly the same position in every sheet.

This means that the paper is extra thick in the region of the thread and problems arise in the paper finishing processes, especially during guillotining, as the stack of paper is markedly higher where the threads overlie each other.

However, as threads have developed and become more complex with the introduction of text, colour shifting features and holographic designs, there has been an increasing need to increase the width of the threads and thus the visual impact associated with the thread.

Though ef

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